Just a quick post that EventDispatcher has been updated with new features including new methods on(), emit(), once() that are similar to Node.js, a new method removeAllListeners(), and a debug function printListeners(). The on() and emit() methods are actually aliases to the addEventListener() and dispatchEvent() methods.

Chris Byerley (aka develephant) who developed Coronium.io and Coronium.gs is using EventDispatcher under the hood for the game server client code. Check out his projects if you’re a Lua / Corona developer.

If you’ve been thinking of having your own virtual private server, here’s a referral link to get $10 credit from DigitalOcean. While I won’t be getting any referral credit until $25 has been spent by you, it’s still a good deal to check it out with the two months credit (if you sign up for the $5/month plan).

In Corona SDK, event listeners can only be added to the global Runtime object or to display objects. In order to broadcast messages to event listeners, the event dispatcher is limited to either one or the other. This limitation places messaging in the two scopes instead of between objects that are supposed to be talking to each other. I’ve seen many examples with display objects that are created solely for the purpose of dispatching events. This just doesn’t feel right to me; so I’m releasing my EventDispatcher, perhaps other developers may find it useful too.

Those who came from the good old Flash 5 days may remember FLEM (FLash Event Model). It was the first listener event model for Flash and ActionScript, and was created by Branden Hall and further developed and maintained by me. I’ve adapted the basic event model mechanism found in ActionScript 2/3 to Lua. This EventDispatcher has a similar interface as the listener model in Corona SDK, with some extra features thrown in (such as optional extra parameters when dispatching events, and returning status).

iPad is turned off by Artist2 (table)
Artist2 is resting
Rested 1
Cowboy1 is drawing a gun
Cowboy2 is drawing a gun
Artist1 is drawing a picture
iPad is turned on by Artist2 (function)
Artist2 is drawing on the iPad
Removed
iPad is turned off by Artist2 (table)
Artist2 is resting
Artist1 is resting
iPad is turned off by Artist1 (table)
Rested 2
Cowboy2 is drawing a gun and shooting a bandit
iPad is turned on by Artist2 (function)
Artist2 is drawing a bandit on the iPad
Mayor collected 42 pieces of gold from Dave

Lua has a table.remove() function that deletes an element from a table at the specified position, or the last element by default. However, it doesn’t work when the table is an associative array (e.g. {name=”swfoo”, domain=”swfoo.com”} ).

Below is a simple function that deletes a key-value pair from a table. One important feature to note is that instead of modifying the original table, it returns a new table.

This innocent-looking PNG image makes a huge difference to iOS apps if you need to target retina display devices. At 640×1136 and named “Default-568h@2x.png”, this default launch image tells the app to run in full retina resolution on devices such as iPhone 5. What’s different with this image is the tiny file size of only 184 bytes. You’re welcome to grab it and use it.